This research aimed to investigate the impacts of a combination of rice husk biochar and organic fertilizer on the physical and chemical properties of soil, the population of soil bacteria, the relative chlorophyll content of leaves, the development of soybean root nodules, and yield components under strongly acid soil conditions. A greenhouse and pot experiment was designed using a randomize complete block design with factorial 2 × 3 treatments and three replications. The experimental treatments comprised two rates of biochar (35 and 70 g/pot) and three rates of organic fertilizer (70, 105, and 140 g/pot). After 100 days of amendment of strongly acidic soils, the results showed that application of treatments B35F70 and B70F140 increased soil pH by 16.80% compared to the control group (CK). On the other hand, treatments B35F140 and B70F105 resulted in an increase of soil electrical conductivity by 66.67% compared to CK. In addition, after 100 days of amendment with treatments B35F105, B35F105, B35F140, B70F105, B70F70, B70F70, and B35F140, organic matter, available phosphorous (P), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), and zinc (Zn), organic matter, available phosphorous (P), potassium (K), calcium (Ca), magnesium (Mg), copper (Cu), and zinc (Zn), significantly increased when compared to the control group (CK). Treatment B35F140 increased relative leaf chlorophyll content and soybean seed weight per plant by 60.76% and 100.56%, respectively when compared to the CK. Furthermore, treatment B35F70 produced 125% more root nodules than CK. Moreover, each amended strongly acid soil resulted with a significant upsurge in total soil bacteria compared to the CK. Overall, statistics proved that a combination of biochar and organic fertilizer improved soil properties and soybean agronomic attributes.

The maturity of compost is involved in the availability of nutrients to crops and improvement of soil properties after fertilization. In the past, the determination of composts maturity mostly required analysis in the laboratory previously and it must consume a lot of time and cost. This study was conducted to use Fourier Transform Infrared (FTIR) spectroscopy and solid¹³C Nuclear Magnetic Resonance (¹³C NMR) spectroscopy to understand the mature characteristics of five type of common composts. The FTIR analysis showed that all composts contained aromatic groups. In addition, the surface of five composts contained the functional groups including hydroxyl group, carboxyl group, amino group etc. However, these functional groups changed along with maturity degree. It is recognized that the aliphatic group located at 2930 cm⁻¹and 2850 cm⁻¹showed a decreasing peak, and amino acid at 1385 cm⁻¹was disappearing gradually due to the decomposition of organic matter by bacteria. There may be used to identify the maturity degree of composts. Increase of aromatic group at 1650 cm⁻¹, carboxy (–COOH) and phenolic OH group at 1385 cm⁻¹may prove the full maturity of composts.¹³C NMR analysis showed that five type of matured composts are mainly consisted with aliphatic groups and aromatic groups. The surfaces of the composts contained C–O bonds (ester, ethers, carbohydrate and other functional groups), COO⁻(carboxyl and ester carbons) and C=O bond (aldehydes and ketones). The strength of different absorptive characteristics of FTIR and¹³C NMR may be a clue to identify the maturity of composts for the design of detective instruments in the future.

Pineapple (Ananas comosus [L.] Merrill) is a commercial crop commonly planted in strongly acid soils in Taiwan. However, aluminum (Al) in strongly acid soils may be toxic and inhibits the root growth of various pineapples. This study evaluated the cell morphology, 1,3-beta-glucan, and malondialdehyde (MDA) of the root apex cells of Al-resistant Cayenne and nonresistant Tainung No. 17 pineapples under two Al concentrations (0 and 300 mu M AlCl3). An observation using transmission electron microscopy indicated no particular variation in the cells of the root apices of the Cayenne pineapple after a treatment with 300 mu M AlCl3. However, apparent changes in the cells of the root apices of the Tainung No. 17 pineapple were observed, for example, separation of the cell wall and cell membrane, enlargement of vacuoles, shrinking and gathering of mitochondria beside the inner cell membrane). The 1,3-beta-glucan (callose) and malondialdehyde (MDA) contents in the Cayenne pineapple were not affected by the Al treatment. However, in the Tainung No. 17 pineapple, those contents showed substantial increases under the treatment with 300 mu M AlCl3, indicating definite damage on the root apices of Tainung No. 17. The results further revealed that the non-Al-resistance pineapple cultivars should be cultivated on the soil that contains low toxic aluminum.

Lettuce is an important vegetable cultivated worldwide, even in regions with highly saline soils. A large amount of research discusses the application of sulfur on the increase of antioxidation in plants. The powder from hoggery desulfurization tanks contained high amounts of sulfur and small amounts of other nutrients for plants. This powder can be added to liquid fertilizer to create high-sulfur liquid fertilizer (HSLF). This study observed the cell morphologies of lettuce root apices under salt stress after the application of HSLF. Lettuce plants were cultivated in hydroponic solutions containing one of two NaCl (0 and 40 mM) and three HSLF (0.0, 1.5, and 3.0 g L⁻¹) concentrations. Salinity reduced the K⁺/Na⁺ ratio in the plant leaves; however, this reduction was smaller in the HSLF-treated plants. Except for phosphate and potassium, nutrient absorption is inhibited under conditions of high salinity. Using scanning electron microscopy, we observed apices more integrated on cell roots after increasing HSLF supplement under non-salt-stressed conditions. In addition, the cells were repaired after increasing the supplement of HSLF under the condition of 40 mM NaCl. Although salt stress reduced plant growth, the reductions were minimized in the HSLF-treated plants. The application of HSLF potentially alleviated salt injury in lettuce root apices and was probably associated with the improvement of phosphorus and potassium absorption and increasing K⁺/Na⁺ ratios in lettuce plants.